Lubricant additive and composition containing same



United States Patent 3,131,149 LUBRECANT ADDITIVE ANB CQMFOSITEGN CONTAINiNG SAh E Albert R. Sabol, Munster, and Eli W. Blaha, Highland, inch, assignors to Standard Gil Company, Chicago, Ill., a corporation of Indiana No Drawing. Filed ept. 4, 1958, Ser. No. 758,924- 15 (Ilaims. (ill. 252-32.7)

The present invention relates to an improved lubricant additive, and lubricant compositions containing the same for meeting requirements of current internal combustion engine lubrication.

Neutralized reaction products of a phosphorus sulfide and a hydrocarbon, particularly olefin polymer, are widely used as detergent-type additives in lubricants, especially in crankcase lubricating oils of internal combustion engines. The use of such additives in lubricant compositions is described in US. Patents No. 2,316,080 and No. 2,316,082 issued April 6, 1943, to C. M. Loane et al. Such detergent-type additives are most eifective under heavy duty, high temperature conditions of engine operation. However, in engines operating under moderate or light duty service and under intermittent operating conditions, wherein low engine jacket and crankcase temperatures prevail, such detergent additives often are of limited effectivenes in combating sludge conditions of the lowtemperature type which may result from extreme oil contamination with combustion chamber blow-by products. For such low temperature operating conditions lubricant detergenttype additives of high ratios of alkaline earth metal to detergent phosphorus are desired. Also, it is desirable to provide a low-temperature detergent-type additive which is effective in preventing the corrosion of copper and silver which are components of bearings, etc. in present day internal combustion engines.

It is an object of the present invention to provide a method of preparing an improved lubricating oil lowternperature detergent-type additive having a high alkaline earth metal to detergent phosphorus ratio. Another object is to provide a lubricating oil additive having a high alkaline earth metal to detergent phosphorus ratio and which possess detergency and bearing corrosion-inhibiting properties. Another object of the invention is to provide an alkaline earth-containing neutralized reaction product of a phosphorus sulfide and a hydrocarbon having a high alkaline earth content, and having detergency properties. Still another object of the invention is to provide a lubricant composition containing the improved additive. Other objects and advantages of the invention will become apparent from the following description thereof.

Broadly, in accordance with the present invention, the foregoing objects are attained by the use of an oil-soluble additive complex obtained by reacting a phosphorus sulfide, e.g., phosphorus pentasulfide, with a high boiling hydrocarbon, as hereinafter described, under conditions to avoid hydrolysis of said reaction product, and subse quently forming a complex by reacting the unhydrolyzed reaction product with a dialkyl dithiophosphorus compound such as Zinc dialkyldithiophosphate and a basic alkaline earth compound in the presence of water and an alkanol of 1 to 3 carbon atoms under the hereinafter described conditions. The resulting products are used in lubricating oils as detergent-type corrosion-inhibiting additives in concentrations of from .002 to 15 Weight percent and may be used in additive concentrates in amounts greater than 15 weight percent and may be used in additive concentrates in amounts greater than 15 weight percent and preferably less than 50 Weight percent.

In the preparation of the phosphorus sulfide-hydrocarbon reaction product, the hydrocarbon is reacted with 3,l3l,l i Patented Apr. 28, 1964 a phosphorus sulfide, such as P 8 P 5 P 8 or other phosphorus sulfides, and preferably phosphorus pentasulfide, P S

The hydrocarbon constituent of this reaction is suitably a high boiling hydrocarbon such as is described in detail in US. 2,316,080, 2,316,082, and 2,316,088, each issued to Loane et al. on April 6, 1943. While the hydrocarbon constituent of this reaction can be any of the type hereinafter described, it is preferably a mono-olefin hydrocarbon polymer resulting from the polymerization of low molecular weight mono-olefinic hydrocarbons or isomono-olefinic hydrocarbons, such as butylenes, or the copolymers obtained by the polymerization of hydrocarbon mixtures containing isomono-olefins and mono-olefins or mixtures of olefins in the presence of a catalyst, such as sulfuric acid, phosphoric acid, boron fluoride, aluminum chloride or other similar halide catalysts of the Friedel-Crafts type.

The polymers employed are preferably mono-olefin polymers or mixtures of mono-olefin polymers and isomono-oleiin polymers having molecular Weights ranging from about 150 to about 50,000 or more, and preferably from about 300 to about 10,000. Such polymers can be obtained, for example, by the polymerization in the liquid phase of a hydrocarbon mixture containing monoolefins and isomono-olefins such as butylene and isobutylone at a temperature of from about F. to about F. in the presence of a metal halide catalyst of the Friedel-Crafts types such as, for example, boron fluoride, aluminum chloride, and the like. In the preparation of these polymers we may employ, for example, a hydrocarbon miXture containing isobutylene, butylenes and butanes recovered from petroleum gases, especially those gases produced in the cracking of petroleum oils in the manufacture of gasoline.

Essentially parflnic hydrocarbons such as bright stock residuums, lubricating oil distillates, petrolaturns, or parafiin waxes, may be used. There can also be employed the condensation products of any of the foregoing hydrocarbons, usually through first halogenating the hydrocarbons, with aromatic hydrocarbons in the presence of anhydrous inorganic halides, such as aluminum chloride, zinc chloride, boron fluoride, and the like.

Other preferred olefins suitable for the preparation of the herein described phosphorus sulfide reaction products are olefins having at least 20 carbon atoms in the molecule of Which from about 13 carbon atoms to about 18 carbon atoms, and preferably at least 15 carbon atoms, are in a long chain. Such olefins can be obtained by the dehydrogenation of parafiins, such as by the cracking of paraffin Waxes or by the dehalogenation of alkyl halides, preferably long chain alkyl halides, particularly halogenated paraffin waxes.

The phosphorus sulfide-hydrocarbon reaction product is prepared by reacting the phosphorus sulfide, e.g., P 8 with the hydrocarbon at a temperature of from about F. to about 600 F., preferably from about 300 F. to about 500 F., using from 1% to about 50%, preferably from about 5% to about 25% of phosphorus suliide; the reaction is carried out in from one to about ten hours. It is preferable to use an amount of the phosphorus sulfide that will completely react with the hydrocarbon so that no further purification is necessary; however, an excess of the phosphorus sulfide can be used, and the unreacted material separated by filtration. The reaction, if desired, can be carried out in the presence of a sulfurizing agent such as sulfur or a halide of sulfur as described in US. 2,316,087, issued to J. W. Gaynor et al., April 6, 1943. It is advantageous to maintain a nonoxidizing atmosphere, for example an atmosphere of nitrogen, in the reaction vessel. Under the above conditions, hydrolysis of the reaction product does not occur.

The additive. compositions of our present invention are prepared by neutralizing an unhydrolyzed phosphorus sulfide-hydrocarbon reaction product, which may be made, for example, by the above process, with a basic alkaline earth compound in the presence of a dialkyl dithiophosphorus compound, water and an alkanol at the reflux temperature of the alkanol. The basic alkaline earth compound can be, for example, the oxide, hydroxide, carbonate or sulfide of calcium, barium, strontium or magnesium, although barium odde is preferred. The alkanol can be methanol, ethanol, propanol or isopropanol, although methanol is preferred. The dialkyl dithiophosphorus compound used during neutralization of the phosphorus sulfide-hydrocarbon reaction product is a dialkyl dithiophosphorus acid, a metallic salt of a dialkyl dithiophosphorus acid or a dialkyl dithiophosphorus ester which decomposes to give a dialkyl dithiophosphorus acid. The preferred dialkyl dithiophosphorus compounds are the pentavalent dialkyl dithiophosphorus compounds such as the dialkyl dithiophosphoric acids, metal salts and decomposable esters, and particularly a zinc dialkyl dithiophosphate although any such compound having pentavaient phosphorus and corresponding to the following general formula is preferred:

P RzO \S 11X wherein R and R are alkyl groups having from one to ten carbon atoms, X is hydrogen or a metal, and n corresponds to the valence required by X.

Neutralization of the phosphorus sulfide-hydrocarbon reaction product with a basic alkaline earth compound in the presence of the alkanol, water and a dialkyl dithiophosphorus compound as identified above, causes complex formation whereby greater amounts of basic alkaline metal are introduced into the product in proportion to detergent phosphorus then during prior normal neutralization methods. The formation of the complex can be carried out directly with the phosphorus sulfide-hydrocarbon reaction product; however, to facilitate handling, it is preferable to form a solution of the unhydrolyzed phosphorus sulfide-hydrocarbon reaction product by dilution with a lubricating oil, such as for example, a 5W oil, although any suitable normally liquid hydrocarbon or other diluent can be used.

The formation of the complex is suitably carried out by adding to the oil-diluted phosphorus sulfide-hydrocarbon reaction product from about 0.10 mole to about 4.0 moles of the dialkyl dithiophosphorus compound per mole of deter ent phosphorus of the phosphorus sulfidehydrocarbon reaction product, and neutralizing the mixture with from about 1 mole to about 4 moles of the basic alkaline earth compound in the presence of from 0.2 mole to 2.0 moles water and from about 1 mole to about moles of the alkanol, per mole of the basic alkaline earth compound and heating the reaction mixture at a temperature corresponding to from about 100 F. to about 180 F. at atmosphere pressure, and preferably at the reflux temperature of the alkanol for a period of from about 1 hour to about 10 hours. The reaction vessel is equipped with a reflux condenser to avoid the loss of alkanol and water vapors. After heating at the reflux temperature for the required time, the temperature is raised to a temperature corresponding to about 200 F. to 400 F. at atmospheric pressure to remove water and alcohol and the product filtered through a suitable adsorbent material such as for example Celite, Attapulgus clay, fullers earth and the like. Naturally, the above temperature ranges may be varied with higher or lower pressures and such variances are to be considered within the scope of our invention.

Products prepared in accordance with the present invention have high alkaline earth metal to detergent phosphorus ratios. Detergent phosphorus is the phosphorus A, of the phosphorus sulfide-hydrocarbon reaction product alone. Such high ratios allow the products to impart increased detergency properties to lubricant compositions per amount of detergent phosphorus present. It follows that less of these high ratio additive compositions may be used to impart suitable detergency properties to a lubricating oil because of the higher alkaline earth metal content. The additives of our present invention have alkaline earth to detergent phosphorus of from about 1 mole to about 5 moles per mole detergent phosphorus. The preferred additives contain barium to detergent phosphorus in ratios of from about 1.25 moles to about 4.5 moles per mole of detergent phosphorus. Although we do not wish to be limited to any theories regarding the greater amount of alkaline earth metal complexes per given amount of detergent phosphorus, it is believed that the presence of the dialkyl dithiophosphorus compound enables a greater amount of alkaline earth metal to complex probably by aiding in solubilizing the alkaline earth metal during the neutralization.

The additive compositions of our invention containing the complexed dialkyl dithiophosphorus compound and high ratio of alkaline earth metal are stabilized, apparently by the additional sulfur of the dialkyl dithiophos phorus compound, against evolution of hydrogen sulfide formed by partial dissociation of the phosphorus sulfidehydrocarbon reaction product under normal conditions of use of lubricating oils in internal combustion engines.

The following example of the preparation of oil-soluble additive complexes of our present invention is for the, purpose of illustration only and is not to be regarded as a limitation of our invention.

EXAMPLE I A butylene polymer having an average molecular weight in the range of from 750 to 800 was reacted at about 450 F. with 15.5 wt. percent P 5 for a period of 5 hours. An amount of the resulting product having 25.4 grams total phosphorus content was diluted with 600 grams of an SAE 5W mineral oil and neutralized with 580 grams BaO in the presence of 720 grams zinc dialkyl dithiophosphate, 5 moles methanol per mole BaO and 0.4 mole water per mole BaO. The neutraliza; tion was carried out at the reflux temperature of the, methanol (160 350 F. to remove methanol and water and filtered through Celite. The filtered 14.99% Ba, 1.27% Zn and 2.15% phosphorus was present in the product in the amount of 0.88%. The ratio of barium to total phosphorus was about 7:1 and the ratio of barium to detergent phosphorus was about 17:1. The product had an alkalinity of 63.6 mg. KOH per gram.

EXAMPLE II 1,336 g. of a diluted phosphorus pentasulfide-butylene. polymer reaction product prepared as in Example 1 and containing one mole of phosphorus was added to g. of zinc dialkyldithiophosphate 1 and diluted with 550g. of SAE 5W mineral oil. The resulting mixture was heutralized with 310 g. barium oxide in the presence of 5 moles of methanol per mole of barium oxide and 0.6, mole of water per mole of barium oxide. The neutraliza: tion was carried out in the same manner as described above in Example 1. The filtered product contained 1.65% phosphorus, 11.8% barium, 0.47% zinc, and 2.83% sulfur. The product had a detergent phosphorus content of 1.3% and the ratio of barium to detergent phosphorus was about 9 to 1.

EXAMPLE III 1.340 g. of a phosphorus pentasulfide-butylene polymer reaction product prepared as in Example I and containlng one mole of phosphorus was mixed with 1.47 g. of. zinc dialkyldithiophosphate and diluted with 500 g. of

Pi-epared from a mixture of 70 mole percent of isopropyl alcohol and 30 mole percent of methyl isobutyl carbinol.

F.) for three hours and then heated toproduct constain 3.41% S, total P. Detergent;

SAE 5W mineral oil. The diluted mixture was then neutralized with 245 g. of barium oxide in the presence of 5 moles of methanol per mole of barium oxide and 0.5 mole of water per mole of barium oxide. The neutralization was carried out in the same manner as described in Example 1 above. The filtered product contained 1.8% phosphorus, 8.66% barium, 0.47% zinc, and 3.3% sulfur, The ratio of barium to detergent phosphorus was about 6.2 to 1.

The effectiveness of the additives of the present invention in inhibiting corrosion toward copper and/ or leadcontaining metals, such as for example, copper-lead alloys, and their oiddation inhibiting properties, are demonstrated by the data in Table 1, obtained by subjecting the above samples to the following Sand Stirring Corrosion Test.

A copper-lead test specimen is lightly abraded with steel wool, washed and naptha, dried and weighed to :the nearest milligram. The cleaned copper-lead test specimen is suspended in a steel beaker, cleaned with a hot trisodium phosphate solution, rinsed with water, and acetone, and dried, and 250 grams of the oil to be tested together with 0.625 gram lead oxide and 50 grams of a 3035 mesh sand charged to the beaker. The beaker is then placed in a bath or heating block and heated to a. temperature of 300 F. (12 F.) while the contents are stirred by means of a stirrer rotating at 75 r.p.m. The contents of the beaker are maintained at this temperature for twentyfour hours, after which the copper-lead test specimen is removed, rinsed with naphtha, dried and weighed. The test specimen is then replaced in the beaker and an additional 0.375 gram of lead oxide added to the test oil. At the end of an additional twenty-four hours of test operation the test specimen is again removed, rinsed, and dried as before and weighed. The test specimen is again placed in the beaker together with an additional 0.250 gram of lead oxide and the test continued for another twenty-four hours (seventy-two hours total). At the conclusion of this time, the test specimen is removed from the beaker, rinsed in naphtha, dried and weighed. In addition to determining the weight loss of the metal specimen, the acidity of the oil in terms of milligrams of KOH per gram of oil is determined at the 24, 48, and 72 hour intervals. The loss in weight of the test specimen is recorded after each weighing.

The following samples were subjected to the above Sand Stirring Corrosion Test:

Sample ASolvent extracted SAE 30 mineral oil.

Sample B-A barium-neutralized hydrolyzed phosphorus sulfide (P S )-polybutene (mol. wt. of about 800) reaction product containing 5.3% Ba, 2.04% P, and 1.17% S and diluted with Sample A to 4.3%.

Sample C-Sample A containing 4.8% of the product of Example 111.

Sample D-Sample A containing 4.8% of the product of Example HI and 0.25% zinc dialkyl dithiophosphate.

Sample ESample A containing 4.8% of the product of 5 Sample F-Sample A containing 2.4% of the product of Example HI and 0.3% zinc dialkyl dithiophosphate. Sample G-Sample A containing 2.4% of the product of Example 111 and 0.4% zinc dialkyl dithiophosphate. Sample H-Sample A containing 2.4% of the product of Example 111 and 0.5% zinc dialkyl dithiophosphate. Sample l-Sample A contaim'ng 2.4% of the product of Example 111 and 0.6% zinc dialkyl dithiophosphate.

Table 1 RESULTS OF SAND STIRRING CORROSION TEST Acidity, mg. KOH/g. oil Wt. Loss, Total mgs. Sample 24 Hrs. 48 Hrs. 72 Hrs. 48 Hrs. 72 Hrs.

The low temperature detergency properties of the complex of the present invention is demonstrated by the data in Table 11, below, which data were obtained in the engine test designed to determine the low temperature detergency of motor oils. The test, known as the L1 Test, having C.R.C. Designation L-1-545 is fully described in C.R.C. Handbook, 1956 Edition, of the Coordinating Research Council, New York. Briefly, the test is conducted in a 1AS1 single cylinder Caterpillar engine operating at 1,000 r.p.m. at a load of 19.8 B.H.P. with an oil temperature to bearings of to F. and a water jacket outlet temperature of to F. and an inlet temperature of 10 to 15 F. below the outlet temperatures. The test is run for 480 hours with inspections at the end of 120, 240, and 480 hour periods for carbon in the ring grooves, expressed in terms of percent groove filled.

The following lubricant composition samples were subjected to the above test and the data in Table II were obtained.

Sample A SAE 30 base motor oil containing 4.5 wt. percent of a product prepared by reacting a butylene polymer having an average molecular weight in the range of about 750 to 800 with 15.5 wt. percent P 5 at about 450 F. for about 5 /2 hours hydrolyzing the resulting product with steam for about 5 /2 hours and neutralizing with barium oxide. The product contained 1.4% P and 7.7% Ba.

Sample B-SAE 30 base motor oil containing 3.2 wt. percent of the product of Example HI. The product contained 1.4% detergent P, 1.8% total P and 8.66% Ba. Prepared from a mixture of isopropanol and methyl isobut'yl carbinol.

For comparison of a metal salt of a phosphorus sulfidehydrocarbon reaction product with a composition in which Example III. zinc dialkyl dithiophosphate is chemically bonded.

Table 11 RESULTS OF L-l TEST Oil Analysis Percent Top Ring Fuel (Calculated) Groove Carbon Ratio Ba Sulfur Inhibitor, Detergent to Deter- Content, Wt.

gent P Wt. Percent Percent percent 120 240 480 percent 1 Deter- Be Hrs. Hrs. Hrs.

gent P Sample A 5 5 to 1 1.0 3 0. 062 0.36 0.75 1 5 Sample B 6 2 to l 1. 0 0.046 0.41 None 1 2 Sample A- 5 5 to 1 0.35 0. 038 0. 212 0.62 1 3 Sample 13 6 2 t0 1 0. 35 0.024 0.212 0.34 13 15 0.35 percent is a low sulfur fuel 2 Zinc dialkyl dithiophospliate 3 Minimum passing concentrat 1.0 wt. percent designates a high sulfur fuel and prepared from a mixture of isopropanol and methyl isobutyl carbinol. ion using 1.0 percent sulfur fuel.

The herein described additive compositions of the present invention can be used as indicated above in varying amounts of from .002 up to about '15 percent in lubricating oils. Although the present invention has been illustrated by the use of the additive compositions in mineral lubricating oils, it is not restricted thereto. Other lubricating oil bases can be used, such as hydrocarbon oils, both natural and synthetic, for example, those obtained by the polymerization of olefins, as Well as symthetic lubricating oils of the alkylene oxide type and the polycarboxylic acid ester type, such as the oil soluble esters of adipic acid, sebacic acid, azelaic acid, etc. it is also contemplated that the various other well known additives, such as antioxidants, antiafoaming agents, pourpoint depressors, extreme pressure agents, antiwear agents, may be incorporated in lubricating oilsconta-ining the additives of our invention.

Concentrates of a suitable oil base containing more than 15 percent, for example up to 50 percent or more, of the additives of this invention done or in combination With other additives can be used for blending hydrocarbon oils or other oils in the proportions desired for the particular conditions of use to give a finished lubricating product containing the additives of this invention.

Unless otherwise stated, the percentages given herein and in the claims are percentages by weight.

Although we have described our invention by reference to specific embodiments and examples thereof, such specific embodiments and examples as have been given are merely -for the purpose of illustration of the invention and are not intended as limiting its scope. It is intended that modifications and variations of the present invention which are apparent from our foregoing description to those :sln'lled in the art are to be considered within the scope of our present invention except as stated in the following appended claims.

We claim:

1. As a new composition of matter, an oil-soluble neutralized complex prepared by the process comprising reacting a high boiling hydrocarbon with from about 1% to about 50% of a phosphorus sulfide at a temperature of from about 150 F. to about 600 F. and neutralizing the unhydrolyzed reaction product at a temperature between 100 F. and 400 F. with a basic alkaline earth compound in mixture with water, from about 1 to moles (per mole of alkaline earth compound) of a Watersoluble monohydroxy alkanol of from 1 to about 3 carbon atoms and from about 0.1 to about 4.0 moles (per mole of phosphorus of the unhydrolyzed reaction product) of a dialkyldithiophosphorus compound having the general formula:

wherein R and R are each alkyl groups having from one to ten carbon atoms, X is selected from the class consisting of hydrogen and zinc and it corresponds to the valence of X.

2. The composition of claim 1 wherein the phosphorus sulfide is phosphorus pentasulfide and the hydrocarbon is a butylene polymer.

3. The composition of claim 1 wherein the basic alkaline earth compound is a basic barium compound.

4. The composition of claim 1 wherein the dialkyl dithiophosphorus compound is zinc dialkyl dithiophosphate.

5. The compositionof claim '1. wherein the water-soluble monohydroxy alkanol is methanol.

6. The composition of claim 1 containing added suitable diluent before neutralization with the basic alkaline earth mpo nd.

7. A lubricant composition comprising a major proportion of anormally liquid lubricating oil andfrom .002 to of the composition of claim 1.

wherein R and R are each alkyl groups having from one to ten carbon atoms X is selected from the class consisting of hydrogen and zinc and it corresponds to the valence of X, and neutralizing the resultant treated unhydrolyzed reaction product With from about 1 to about 4 moles of a basic alkaline earth oxide per mole of'phosphorusat a temperature of from about F. to about 180 F., Water and a Water-soluble monohydroxy alkanol having from 1 to about 3 carbon atoms under reflux conditions for a period of time within the range of from about 1 to about '10 hours.

9. The composition of claim.8 wherein the phosphorus sulfide is phosphorus pentasulfide and the hydrocarbon is a butylene polymer.

10. The composition of claim 8 wherein the basic al-' kaline earth oxide is barium oxide.

'11. The composition of claim 8 wherein X is defined as Z1110.

'12. A lubricant composition comprising a major proportion of a normally liquid mineral lubricating oil and from about 002% claim 8.

13. As a new composition of matter, an oil-soluble neutralized complex prepared by the process comprising reacting a high boiling hydrocarbon with from about 1% to about 50% of a phosphorus sulfide at a temperature of from about F. to about 600 F., treating the resulting unhydrolyzedreaction product with from about 0.1 to about 4.0 moles, per mole of detergent phosphorusof the unhydrolyzed reaction product, of a mntavalent dialkyldi-thiophosphorus compound having the general formula:

wherein R and R are each alkyl groups having from one to .ten carbon atoms, X is selected from the class consisting of hydrogen and zinc and n corresponds to the valence of X and neutralizing the resultant treated unhydrolyzed reaction product at a temperature of from about 100 F. to 400 F. with from about 1 to about 4 moles of a basic barium compound per mole of phosphorus, 0.2 to 2.0 moles of water per mole of basic barium compound and from about 1 mole to about 10 moles of a Water-soluble monohydroxy alkanol of from 1 to about 3 carbon atoms.

14. An addition agent concentrate for lubricating oils comprising essentially a major proportion of a lubricating oil containing more than about 15 of an oil-soluble neutralized complex capable of dilution with a lubricating oil to a concentration in the range of from about .002 to about 15%, said oil soluble neutralized complex being prepared by the process comprising reacting -a hydrocarbon with from about 1% to about 50% of a phosphorus sultide at a temperature of from about 150 to about 600 F, and-neutralizing the resultant unhydrolyzed reaction product with a basic alkaline earth compound in the presence of water, a Water-soluble monohydroxy alkanol to about 15 of the composition of wherein R and R are each alkyl groups having firom one to ten carbon atoms, X is selected from the class consisting of hydrogen and zinc, and it corresponds to the valence of X.

15. As a new composition of matter, an oil soluble neutralized complex prepared by the process comprising reacting a butene polymer with from about 1% to about 50% of a phosphorus sulfide at a temperature of from about 150 to about 600 F., treating the resulting unhydrolyzed reaction product with from about 0. 1 to about 4.0 moles, per one mole of phosphorus contained in the unhydrolyzed reaction product, of a zinc dialkyl dithiophosphate in which the alkyl groups each contain from 1 to 10 carbon atoms to form a reaction mixture, neutralizing the reaction mixture at a te perature in the range of from about 100 F. to about 180 F. with from about 1 to about 4 moles of barium oxide per mole of phosphorus in said reaction product in the presence of from about 0.2 to about 2. 0 moles of Water per mole of barium oxide and from about 1 to about 10 moles of methanol per mole of barium oxide for a period of time of from about 1 to about 10 hours under methanol reflux conditions.

References Cited in the file of this patent UNITED STATES PATENTS 2,688,612 Watson Sept. 7, 1954 2,799,653 'Scanley July 16, 1957 2,806,022 Sabol Sept. 10, 1957 2,900,376 Sabol et al. Aug. 18, 1959' 

1. AS A NEW COMPOSITION OF MATTER, AN OIL-SOLUBLE NEUTRALIZED COMPLEX PREPARED BY THE PROCESS COMPRISING REACTING A HIGH BOILING HYDROCARBON WITH FROM ABOUT 1% TO ABOUT 50% OF A PHOSPHORUS SULFIDE AT A TEMPERATURES OF FROM ABOUT 150*F. TO ABOUT 600*F. AND NEUTRALIZING THE UNHYDROLYZED REACTION PRODUCT AT A TEMPERATURE BETWEEN 100*F. AND 400*F. WITH A BASIC ALKALINE EARTH COMPOUND IN MIXTURE WITH WATER, FROM ABOUT 1 TO 10 MOLES (PER MOLE OF ALKALINE EARTH COMPOUND) OF A WATERSOLUBLE MONOHYDROXY ALKANOL OF FROM 1 TO ABOUT 3 CARBON ATOMS AND FROM ABOUT 0.1 TO ABOUT 4.0 MOLES (PER MOLE OF PHOSPHORUS OF THE UNHYDROLYZED REACTION PRODUCT) OF A DIALKYLDITHIOPHOSPHORUS COMPOUND HAVING THE GENERAL FORMULA: 